Circuit Breaker Test Equipment Information

Circuit breaker test set from Megger


Circuit breaker test equipment tests and analyzes the functioning of circuit breakers to ensure they are operating properly, safely and within specification. Test equipment performs the basic function of connecting and disconnecting electrical power to the breaker. 




Test equipment evaluates various aspects such as the current, voltage, contact resistance, switching time, and frequency.  Often simulated faults are tested, as well as other tests. Test results are then examined to determine if the circuit breaker is functioning to its specifications.

Some equipment will perform these tests automatically while other equipment requires the operator intervention to complete the testing process. Results from completed tests can be provided on a display screen, via analog meters, printed out or sent as data to a computer.  Test equipment may have an interface such as USB or ethernet so results can be transmitted to a remote device.




Test equipment can range from simple devices that perform the most basic tests, such as overcurrent, to devices that conduct multiple tests and store the results.  The power used for testing depends on the breaker type. Choices include DC and  AC  in either single or three-phase power. Different kinds of circuit breakers also require different kinds of test equipment.  Some test equipment may only work on one kind of breaker such as single phase where others can be more universal. Some breakers include other protective functions, such as arc fault and ground fault, which may require additional tests.  More advanced breakers may require special tests such as for reclosers.


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